If they lost a game before then they damn well would. If not I still think they will get in comfortably but starting as a 4 seed is not a good look for them. A Bama loss would put a lot of pressure on them.
Maybe make the rule that if the ACC has a playoff contender and might need a little help (like if Clemson lost a game) and the other division had no teams with 3 or fewer losses there was an option to bring ND in?
Only do it if it benefits the ACC and ND gets no money from it. This would be a nice financial boost for the conference.